The present invention generally relates to spring mechanisms and more particularly to a flexural disc spring for acting as an isolation mount for the tail mass of an underwater sound transducer.
Several types of tail mount isolation springs are in use. Multiple layers of thin paper provide the desired stiffness quietly and reliably, but as maximum load requirements increase, the elastic limit of the layered paper is reached and the required stiffness cannot be maintained over the entire load range. Composite plastic materials used in the bulk compression mode provide the required stiffness over whole load range, but produce noise levels which interfere with transducer operation. Other known springs are available that provide the proper stiffnes at low cost, but have areas of high stress concentration and high relative motion which cause low fatigue strength and noise. These springs also have complex stress behavior not easily subjected to mathematical analysis, so that stress levels and dynamic stiffness of these configurations cannot always be accurately predicted.